The present invention relates to a drive unit of a conveyer installed in a horizontal path or an inclined path; and, more particularly, the invention relates to a drive unit of a conveyer capable of saving space and providing improving assembling and inspection efficiencies.
A conventional drive unit for conveyer is disclosed in Japanese Utility Model Publication (JU-B) No. 63-48621 (1988) (Laid Open (JU-A) No. 60-183784 (1985)), for example. This conventional drive unit has a reduction gear mechanism and a motor which is mounted directly on an inclined upper surface of the reduction gear mechanism so as to be slidable along the inclined upper surface. This drive unit is advantageous in that the space for the drive unit in the machine room of the conveyer is minimized by stacking the reduction gear mechanism and the motor, and a margin for manufacturing accuracy is provided by adopting a drive arrangement such as a chain and sprocket or belt and pulley, for transmitting drive power between the motor and the reduction gear.
Another example of a conventional drive unit for a conveyer also is disclosed in the above-referenced Japanese Utility Model Publication. In this second example, a motor is mounted on the upper side of the reduction gear mechanism by stud bolts fixed to the reduction gear housing. The stud bolts used for fixing the motor also are used for adjusting the height of the motor from the upper surface of the reduction gear mechanism, thereby to adjust the tension of a chain provided for transmitting rotation of the motor to the reduction gear. This conventional drive unit also has the same advantage of the first mentioned drive unit.
The above-mentioned two conventional drive units, however, have a disadvantage in that the tooth flank inspection of the reduction gear may be performed only partially because the opening for an inspection port in the reduction gear housing cannot be made wider since the motor is mounted on the upper side thereof. Further, the drive units each have a disadvantage of an increased manufacturing cost since the structure needs to add the motor-mounting part to the inspection port on the top of the reduction gear housing. Furthermore, the first-mentioned conventional drive unit, which has the motor mounted on the inclined upper surface of the reduction gear housing, has a disadvantage in that when the motor is lifted up and mounted on the reduction gear mechanism, the work cannot be performed easily in that the motor-leg plane is parallel to the motor-mounting part on the inclined top surface of the reduction gear housing, that is, providing unstable balancing condition for the motor due to the inclination of the top surface of the reduction gear housing.
Further, another example of a conventional drive unit for a conveyer is disclosed in Japanese Patent Application Laid Open No. 62-280186 (1987). The drive unit is provided with a table whose sole purpose is to support the drive motor. The table comprises a pair of side plates and an upper plate fixed to the pair of side plates. A reduction gear is disposed under the upper plate of the table so as to be sandwiched by the pair of side plates, and a motor is mounted on the upper plate of the table so as to be movable thereon.
This conventional drive unit also has the same advantage as the above-mentioned conventional drive units; however, the drive unit has a disadvantage in that the tooth flank inspection of the reduction gear may be performed only partially since the opening for an inspection port cannot be made wider, even though the assembling work may be performed under a stable balancing condition for the motor. Further, the drive unit has a disadvantage of increased manufacturing cost since the reduction gear housing must be enlarged in size when the opening for the inspection port is widened, and the table for supporting the motor also is needed.